Training and the right gear spark perfect fence for irrigation scheme
The Trangie-Nevertire Irrigation Scheme (TNIS) serves 90 farms that span a total land mass of 101,984 hectares (251,900 acres) with the scheme irrigating just over a 10th of that area. Crops grown under irrigation in the area include grains, cotton, oil seeds, wheat, pasture, lucerne and vegetables, and the annual additional production attributable to the scheme's irrigation is $35 million.
The scheme, which has its roots in the mid 1960s with 240 kilometres of channel, was built in 1970 at a cost of $1.1m with the first commercial water flowing in 1971. The main channel is 108km long, with 35.5km of subsidiary delivery channels. Beginning in the mid 2000s, the TNIS traded water entitlements that were likely to be saved from the modernisation and received $115m to upgrade the irrigation-delivery system and provide a stock and domestic pipeline from the Federal Government's PIOP (Private Irrigation Operators Program). It was a project 10 years in the making.
Biggest undertaking globally
TNIS Chairman Jim Winter says, "Reconstruction and lining much of the channel system was an integral part of saving water from seepage and other in-stream losses. After trials we chose Firestone rubber lining, an EPDM membrane, because of the speed at which it could be installed, the local support and a great warranty. It's the largest undertaking for this type of project any where in the world by Firestone, and has already achieved beneficial outcomes for the farmers and the environment."
Based on farmer experience in the region, they chose a Weston-style electric fence to protect the liner from wandering livestock and wild and feral animals. (Westonfence is popular in north-west NSW.)
The scheme's site co-ordinator Rob McCutcheon says, "We particularly needed protection from kangaroos, but in some more heavily timbered areas, the roos were getting through an earlier-constructed fence that had a poorly thought-out and constructed system, which had been cheap."
Having invested so much money in modernising the scheme, the fence needed to be brought up to scratch.
"We needed to fix it," Rob says, so they began researching solutions.
After recommendations from the Trangie branch of Delta Agribusiness (which has 25 stores across NSW), Rob approached Gallagher for advice.
"I wanted a presentation to the TNIS Committee on the critical requirements of electric fencing, including where and why our existing fence was lacking. Then how we could give our landholders the best possible outcome, with the most effective fence possible that was still going to be cost effective, bearing in mind costs already outlaid."
Swathe of failures
Rob says, "During the comprehensive presentation, the committee quickly realised that while the Weston fence was great, our electric-fencing system was inadequate — on nearly every level. The energizers were too small for the job, the solar panels and batteries were inadequate, the earth system was incorrect, insulators were the wrong type, and cabling was the wrong size. It was just a multitude of issues leading to failure."
The committee asked Ian Thompson, Gallagher's Territory Manager for Central and Western NSW, to review the whole system — more than 222km of electric fencing when complete, and prepare recommendations and a plan to modify the original fencing to match TNIS's need to keep stock away from the liner.
The accepted plan included replacing all the energizers, modifying the fence and giving more attention to the earth system on the existing fence, with the remaining fence to be constructed to Gallagher's recommendations.
"Peter Weston, co-owner of the Westonfence system, concurred with Gallagher's recommendations, which added to the confidence in our decision to go with Gallagher — he also recommends and uses the Gallagher system."
Attention to detail
Gallagher's plan included 13 of the 2800 i Series Energizers — one about every 20km — with four of the smaller 1800 iSeries Energizers on the shorter channel reaches. The i Series have Controllers that can be put where they are easily seen (not necessarily next to the energizer), allowing the fence's condition and energizer performance to be monitored. These Energizers can also be controlled with a Remote and Fault Finder, meaning no time is wasted returning to the energizer to turn it on or off. Fence monitors strategically placed divide the fence system into zones, making it quick and easy to locate a fault (on the Controller, the number of the monitor near the fault changes colour).
TNIS's energizers all run on solar units and have lightning diverters fitted. XL high-conductive lead-out cable, wire end-strain insulators and Spiralfast wire joiners complete the robust, effective fence. (Spiralfasts have a special spiral design and gritted coating which tightly grips the wire, and are easily applied by hand, requiring no tools. With a 10-year guarantee, they reinforce the wire — even under impact.)
Training a vital component
Rob says, "As the repaired sections have been coming online, it's apparent that our liner is now much better protected, and the roos are staying on the right side of the fence. The committee is now comfortable our assets are well protected."
However, while it was important to the TNIS Committee that effective equipment was used, Gallagher's proposed training of the fencing contractors was equally part of the appeal.
"On top of that initial training, regular phone contact and visits have really helped the contractors to get the new sections right — first time.
"Construction is still underway of fences on some outer reaches, and the training given to both our fencing contractors as well as our staff by Gallagher has been of great value to help get the job right. One contractor, who has been installing Westonfence for many years, will change to Gallagher's recommended on any future jobs — particularly with regards to connection and earthing.
"Voltage has increased almost three fold for the full length of our channel fence system thanks to the recommendations of Gallagher and new equipment; we're getting 6,000 to 9,000 volts as the norm, up from the 1,000 to 3,000 volts of the system we began with."
"The i Series monitors have assisted initial set-ups and tests, and will allow staff to monitor for faults quickly and without fuss down the track. It's a big time saver with so many kilometres of fence to maintain, allowing staff to focus more on their key function of supplying water in a timely manner to our members."
Rob says, "The combination of the Westonfence and Gallagher i Series Energizers is a great for keeping all animals in their right place, and will extend the life of our rubber liner. Along with rebuilt channels, new structures, new Rubicon water-control gates and water meters, the rubber lining will allow the efficient delivery of over 40,000 megalitres of irrigation water to 50 irrigator members when water is available. The pumps and channel system can deliver up to 700 megalitres per day if need be.
"Electric fencing is a great and economical way to ensure all types of animals remain where you want them — if done properly — and thanks to Gallagher and the fencing team, we have now achieved this."